Point sample opacity/alpha in Adobe Photoshop?

Question

I opened a PNG containing an alpha channel in Photoshop and wanted to get the opacity / alpha of a given point in the PNG file, so that I could match that opacity in a new photoshop layer. How can I do this? is there any way to get an alpha value at a point the way the color sample tool gives RGB values at a given point?

Solution

1. Open the Info palette
2. Click on the palette option in the top right corner and choose Panel Options...
3. Where it says "Second Colour Readout", choose Mode: Opacity
4. Hit "OK"

In the info palette it will now tell you the opacity level of wherever you put the mouse.

Comments

[Josh]

Perfect! I knew there was a way to do this.

[MSC]

Hmmm. I am getting 100% which is plainly incorrect as I can see the underlying layers through the area I am sampling. It feels like 10%. What could I be doing wrong?